1. Field of the Invention
The present invention relates to a reciprocating compressor, and in particular to a reciprocating compressor which is configured to support a piston elastically and to prevent breakage of the piston and other construction parts abutting on the piston by limiting a stroke distance of the piston by installing elastic members (coil springs) to the front and rear of the piston.
2. Description of the Prior Art
In general, a compressor is for converting mechanical energy into latent energy of compressed fluid. Generally compressors can be classified as a reciprocating type, a scroll type, a centrifugal type and a vane type.
FIG. 1 is a transverse-sectional view illustrating the conventional reciprocating compressor.
As depicted in FIG. 1, the conventional reciprocating compressor includes a container 10 having a certain inner space; a frame unit 30 disposed in the container 10; a reciprocating motor 20 installed in the frame unit 30 in order to generate a driving force; a cylinder 50 installed at the center of the frame unit 30; a piston 60 performing a linear reciprocating motion into and out of the cylinder 50 by the driving force of the reciprocating motor 20; a valve unit 70 installed at the front of the frame unit 30 and the piston 60 so as to suck/discharge gas into the cylinder 50 by using pressure difference generated by the linear reciprocating motion of the piston 60; and a spring unit 80 installed at the frame unit 30 in order to support the linear reciprocating motion of the piston 60 elastically.
The frame unit 30 consists of a front and a rear frames 31, 32 respectively installed at the internal front and the internal rear of the casing 10 and a middle frame 33 installed between the front and the rear frames 31, 32.
The reciprocating motor 20 includes an outer stator 21 fixed between the middle frame 31 and the rear frame 30; an inner stator 22 inserted into the outer stator 21 and spaced therefore by a certain interval; a wound coil 23 wound around the outer stator 21; and a mover 24 installed between the outer stator 21 and the inner stator 22 and connected to the piston 60 so as to perform a linear-reciprocating motion.
The cylinder 50 is horizontally installed at the center of the front frame 40 and maintains a certain interval with respect to the reciprocating motor 20.
The piston 60 is inserted into a through hole 51 of the cylinder 50 so as to form a compression chamber (P), and the end of the piston 60 is connected to the mover 24.
A discharge pipe 2 communicating with the valve unit 70 is installed at the front of the container 10, and a suction or intake pipe 1 is installed at the rear of the container 10.
The valve unit 70 includes a discharge cover 71 for covering the compression chamber (P) of the cylinder 60; a discharge valve 72 arranged inside the discharge cover 71 for opening/closing the compression chamber (P); a valve spring 73 for supporting the discharge valve 72 elastically; and a suction valve 74 combined with the front of the piston 60 and opening/closing a gas suction flow path (F) formed inside the piston 60.
The spring unit 80 includes a spring support 81 directly connected to the rear of the piston 60 or the mover 24; a front coil spring 82 installed between the spring support 81 and the front frame 31; and a rear coil spring 83 installed between the spring support 81 and the rear frame 30.
Hereinafter, the operation of the conventional reciprocating compressor will be described.
When power is supplied to the reciprocating motor 20 and a current flows in the wound coil 23, the mover 24 performs the linear-reciprocating motion by magnetic flux formed by the outer stator 21 and the inner stator 22.
Accordingly, the piston 60 connected to the mover 24 performs the linear-reciprocating motion into the through hole 51 of the cylinder 50.
At the same time, gas is sucked through the suction pipe 1 of the container 10 and the suction flow path (F) of the piston 60, flows into the compression chamber (P) by the operation of the valve unit 70 and is discharged through the discharge pipe 2, and that operation is performed repeatedly.
When the piston 60 reaches a top dead center position (where the piston fully compresses the compression chamber), the spring support 81 is elastically abutted supported by the front coil spring 82. On the contrary, when the piston 60 reaches a bottom dead center position (where the piston fully expands the compression chamber), the spring support 81 is elastically abutted by the rear coil spring 83.
The piston 60 performs the linear-reciprocating motion within a fixed stroke distance, and the linear-reciprocating motion is performed elastically by the front and the rear coil springs 82 and 83.
However, in the conventional reciprocating compressor, when a stroke distance of the piston is not controlled due to an improper operation or an initial position of the piston deviates from a proper position due to fabrication error and assembly error of construction parts, etc., not only the piston but also construction parts abutting on the piston may be damaged due to collision.